The Susceptible Host, Part II

Oct. 1, 2008
In the chain of infection, there are many areas that the dental health-care professional has little control over.

by Noel Kelsch, RDHAP

In the chain of infection, there are many areas that the dental health-care professional has little control over. The susceptible host is an area that all dental health-care professionals have a lot of control over. Simply getting vaccinated against influenza can save your life as well as your patients' lives.

It was on a Friday, about four in the afternoon, when I learned all I ever wanted to know about being a susceptible host. I had taken my best friend, Melissa, to another session of chemotherapy. I felt just a little "off." My muscles ached and I did not feel like I could stay up any longer. Maybe it was the Candy Land game with her 5-year-old son, or the four days of trying to help Melissa get through the pain in the middle of the night, or the air conditioning in the car. I was not sure. My chest felt heavy. I felt a chill and I noticed my right hand trembled for a moment. I decided to stop at my doctor's office and get an antibiotic or just reassurance that I was doing too much.

"Did you get a flu shot this year?" my doctor asked.

"No, things have been too busy and I just did not have time," I replied.

He told me I needed an X-ray and to go to the hospital. I told him I would just go home and lie down and everything would be fine on Monday. He looked me in the eye, touched my shoulder, and said, "You are going to the hospital."

As I drove up that ramp that I had dropped Melissa off at so many times before, I realized that I would not be walking in on my own. I honked the horn and passed out. I was on life support for five days and in the intensive care unit for 10 days. I missed four months of work. I used one of my nine lives on this event, and my family and friends learned about the power of prayer.

I do not remember much, and somehow I think that is for the best. What happened to me could happen to anyone. I had a virus called influenza. Leading up to this event, I did not take care of myself or get the rest that my body needed. My lungs were not prepared to fight against this virus. They were filled with fluid in a matter of minutes. My doctor told me that if I had gone home to lie down instead of going to the hospital, I would not be here to write this article.

What is the flu?

According to the Centers for Disease Control (CDC), influenza — more commonly referred to as "the flu" — is a highly contagious viral infection of the nose, throat, and lungs. Influenza occurs most often in the late fall, winter, and early spring. It is a serious infection that afflicts more than 60 million Americans every year. Other mild respiratory illnesses and even intestinal syndromes are often mistakenly referred to as the flu.

This virus is very easily spread via aerosolized or droplet transmission from infected persons to susceptible persons. In the U.S., annual attack rates are 5% to 20% of the population, and influenza activity peaks from December to March (or later), with February being the most common peak month.1

Influenza has a substantial morbidity rate. An average of 36,000 Americans die from influenza-related complications each year. Mortality is most common in elderly persons, but deaths do occur in other age groups, including children. Hospitalizations due to complications from influenza are highest at the extremes of age, with infants and toddlers hospitalized at rates comparable to elderly persons.2

Influenza onset is abrupt and complications can be severe. Following a one- to four-day incubation period (during which asymptomatic persons may transmit the virus), influenza is marked by abrupt onset of fever (up to 104º F), myalgia, sore throat, and a nonproductive cough. Additional symptoms may include rhinorrhea, headache, chills, photophobia, and malaise. Children may also exhibit symptoms uncommon in adults (e.g., diarrhea, vomiting, and nausea).3

The most common complication of influenza is secondary bacterial pneumonia, which I experienced. Influenza is also associated with other serious illnesses, including encephalopathy, Reyes syndrome, myocarditis, and pericarditis.4

How can I be protected?

Please consider this a call to action. Please get your flu shot. Just as I almost lost my life to this disease because I was too busy, skipping your vaccination may affect both you and your patients. You may not know you have this disease and be transmitting it up to two days before symptoms appear.

Len Novick, executive director of the National Foundation for Infectious Diseases, stated, "Vaccination is the single most effective method of prevention of this life-threatening disease." Influenza viruses mutate, so annual vaccination is necessary. The CDC and World Health Organization predict which three strains of the virus will be prevalent and develop a vaccination around that prediction. This is done in February for the following winter.5

Vaccine efficacy is affected by the age and immune status of recipients and the match between vaccine and circulating influenza strains. The majority of children and young adults develop high antibody titer levels following vaccination, correlating with protection against similar circulating viral strains. Postvaccination titers are lower in elderly persons, and efficacy against influenza infection is lower in this population. While it may not prevent infection, the influenza vaccine is 30% to 70% effective in preventing hospitalization for pneumonia and influenza in elderly persons not living in nursing homes or similar chronic-care facilities. Influenza vaccine is 80% effective against influenza-related death in elderly persons.6

The CDC's Advisory Committee on Immunization Practices (ADCIP) reported that the best way to protect against influenza is to receive an influenza vaccination every year. While anyone can get vaccinated, health authorities make specific recommendations for those at higher risk of complications. This includes adults 50 and older, children 6 months through 18 years of age, and anyone with a chronic medical condition (e.g., asthma, diabetes, heart disease). Health-care workers, parents, and others who live or work around people at increased risk of influenza should get vaccinated as well to help reduce the risk of spreading the virus to susceptible people. Individuals with severe hypersensitivity to eggs and those who have had a previous vaccine-associated allergic reaction should avoid immunization.

The National Foundation for Infectious Diseases reassures that influenza vaccines have proven to be very safe.5 The inactivated vaccine has been available in the U.S. since the 1940s. It is approved for use in all persons 6 months of age and older. Mild and transient local reactions (e.g., soreness, indurations) are the most common adverse events associated with inactivated vaccine. Systemic symptoms (e.g., fever, malaise, chills) are rare (<1% of vaccine recipients) and usually transient, lasting one to two days.

The live attenuated vaccine has been available for use in the U.S. since 2003. It is approved for use only in healthy persons 2 to 49 years of age.† ("Healthy" indicates persons who do not have an underlying medical condition that predisposes them to influenza complications.) The live attenuated vaccine is not approved for use in anyone outside this age range or persons with asthma, reactive airway disease or other chronic pulmonary or cardiovascular conditions, metabolic disease (e.g., diabetes), renal disease, hemoglobinopathies (e.g., sickle cell disease), immunosuppression, and children receiving long-term aspirin therapy. Anyone receiving the live vaccine should avoid close contact with immunocompromised persons for 21 days.7,8

All high-risk persons should be vaccinated annually.

For optimal protection, the following persons should be vaccinated annually:

  • Adults 50 years of age and older
  • Children 6 months through 18 years of age
  • Children younger than 9 years of age being immunized for the first time will require two vaccines at specific intervals (see prescribing information for product used for acceptable dosing intervals)
  • Health-care workers

Anyone at least 6 months of age with certain risk factors, including:

  • Asthma or other pulmonary disorder
  • Cardiovascular disease
  • Metabolic diseases (e.g., diabetes), renal dysfunction, hemoglobinopathies or immunosuppression
  • Conditions that can compromise respiratory function, handling of respiratory secretions, or that increase risk for aspiration (e.g., cognitive dysfunction, spinal cord injuries, seizure disorders, other neuromuscular conditions)
  • Long-term aspirin therapy (for children 6 months to 18 years of age)
  • Women who will be pregnant during influenza season
  • Anyone who comes in direct contact with anyone at high-risk (including infants younger than 6 months who cannot themselves be vaccinated)
  • Anyone wishing to reduce his or her risk of contracting influenza

Antiviral drugs used for chemoprophylaxis or treatment of influenza are adjuncts to vaccine but are not substitutes for annual vaccination. Nonpharmacologic interventions (e.g., frequent handwashing, keeping social distance, and improved respiratory hygiene, including covering your mouth when you cough or sneeze)5 are reasonable and inexpensive. These strategies have been demonstrated to reduce respiratory diseases but have not been studied adequately to determine if they reduce transmission of influenza virus. Similarly, few data are available to assess the effects of community-level respiratory disease mitigation strategies (e.g., closing schools, avoiding mass gatherings, or using masks) on reducing influenza virus transmission during typical seasonal influenza epidemics.9,10

Dental health-care professionals have a responsibility to their patients and themselves to use all measures to prevent disease. Simply getting vaccinated against influenza can help stop the spread of this life-threatening disease.

Common Symptoms*

  • Fever (up to 104° F)
  • Chills (sometimes shaking)
  • Muscle aches and pains
  • Sweating
  • Dry cough
  • Nasal congestion
  • Sore throat
  • Headache
  • Malaise
  • Fatigue
* Some or all of these symptoms may be present

About the Author

Noel Brandon Kelsch, RDH, is a freelance cartoonist, writer, and speaker. Noel's cartoons can be seen in RDH magazine and her articles have been published in both dental and nursing trade magazines, as well as books. She has received many national awards including Colgate Bright Smiles Bright Futures, RDH/Sunstar Butler Award of Distinction, USA magazine Make a Difference Day award, President's Service award, Foster Parent of the Year, and is a five-time winner of the Castroville (Calif.) Artichoke cook-off! Her family lives in Moorpark, Calif. She can be contacted at [email protected].

† On October 24, 2007, CDC's Advisory Committee on Immunization Practices (ACIP) recommended expanding the use of the nasal influenza vaccine LAIV (FluMist®) to include healthy children ages 2 to 4 (24 to 59 months old) without a history of asthma or recurrent wheezing. The vaccine continues to be recommended for healthy persons ages 5 to 49 years who are not pregnant.


National Foundation for Infectious Diseases
CDC. Prevention and Control of Influenza: Recommendation of the Advisory Committee on Immunization Practices (ACIP) 2008
CDC Influenza Branch Weekly Influenza Update

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5 Personal interview with Len Novick, excutive director of the National Foundation for Infectious Diseases.
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9 Centers for Disease Control Prevention and Control of Influenza Recommendations of the Advisory Committee on Immunization Practices (ACIP), 2007 Anthony E. Fiore, MD, David K. Shay, MD, Penina Haber, MPH, et al.
10 Inglesby TV, Nuzzo JB, O'Toole T, Henderson DA. Disease mitigation measures in the control of pandemic influenza. Biosecur Bioterror 2006;4:366-375.